1. Field of the Invention
The present invention relates to a single lens reflex camera or a camera system and particularly to a single lens reflex camera or a camera system comprising in combination a camera main body and a view finder unit formed as a unit against said camera main body.
Said view finder unit formed as a unit means not only those made as an exchangeable adapter unit which can be attached to and detached from a camera main body as desired for systemization of a camera, but also those assembled beforehand as a unit against a camera main body to increase the efficiency of a camera assembly operation and fixedly provided on the camera main body during a final assembly stage or in a course of the camera assembly operation.
2. Description of the Prior Art
A single lens reflex camera having for example a mounting means, such as an accessory shoe to permit the mounting of a device such as a flash lamp, requiring an electrical signal related to the operation of a shutter device as a synchronous signal for actuating the device, where such accessory shoe is provided at a view finder unit part has been known well heretofore.
On the other hand, nowadays, due to the limited space available within a camera main body, when an additional device such as a data photo-taking device, etc. for example is provided with the camera, the device is built into the view finder unit part and an electrical signal related to operation of the shutter device is used as a synchronous signal for having the actuation of the device controlled in order to simplify the control over its operation.
And in a single lens reflex camera provided with a device having its actuation controlled by an electrical signal related to the operation of the shutter device as mentioned above, and/or a means to mount said device, provided at its view finder unit, when said view finder unit is to be made in the form of a unit independent of a camera main body, that is when the view finder is to be made beforehand as a unit to be later connected against the camera main body for better efficiency of camera assembly operation, or where the view finder unit part is to be made as an exchangeable type adapter unit which can be attached to and detached from the camera main body for systemizing a camera, it will be necessary to give special considerations for a form of electrical connections between said camera main body and the view finder unit.
That is, for example, even when the view finder is made beforehand in the form of unit to be later connected against the camera main body for better efficiency in the camera assembly operation as in the former case, if the electrical connection between said view finder part and the camera main body is done by lead wires etc. as has been done in conventional cameras, the connection of said lead wires is quite a complicated operation, thus impairing the advantages in efficiency in the camera assembly operation obtained by forming the view finder part as a unit.
On the other hand, when the view finder unit body is made as an exchangeable type adapter unit which can be freely attached to and detached from the camera main body for systemization of the camera as in the latter case, is provided separately connecting cord or cable, etc. for electrically connecting a synchronous switch (which is so arranged as to provide a synchronous signal related to the operation of the shutter device) at the camera main body and the view finder adapter unit or above mentioned device provided at said view finder adapter unit may be used. The disadvantages of making the connections in this way are, however, that said connecting cords or cables are apt to constitute obstacles in handling the camera, and that said cords or cables are apt to be inadvertently dislocated during the preparation for taking a photograph, making the above mentioned device provided at the view finder adapter unit totally inoperative.